p-Toluenesulfonic acid monohydrate → (2S,4R,E) 4,5-Bis(4-fluorophenyl)-1-[(4-methyl-1,3-dioxan-2-yl)ethenyl]-2-(1-methylethyl)-1H-imidazole

Beteiligte Stoffe

Reaktionsschritte

A mixture of (E)-3-[4,5-bis(4-fluorophenyl)-2-(1-methylethyl)-1H-imidazol-1-yl]-2-propenal (2.01 g), p-toluenesulphonic acid monohydrate (0.316 g) and (R)-(-)-butane-1,3-diol (98%, 1.37 g) in toluene (130 ml) was heated under reflux with a Dean-Stark trap for 20 h. The mixture was concentrated to ca. 30 ml and purified by FCC eluting with System A (1:4) to give the title product (1.78 g), as a white solid. δ(CDCl3) 1.23 (d, J 6 Hz, 3H, CH3CH--O), 1.42 (d, J 7 Hz, 6H, (CH3)2CH), 1.55-1.8 (m, 2H, OCH(CH3)CH2CH2O), 3.20 (septet, J 7 Hz, 1H, (CH3)2CH), 3.7-3.9 (m, 2H, CH2O), 4.05-4.16 (m, 1H, O--CH(CH3)), 4.95 (d, J 5 Hz, 1H, CH=CHCH(O)2), 5.32 (dd, J 15 and 5 Hz, 1H, NCH=CH), 6.76 (dd, J 15 and 1 Hz, 1H, NCH=CH), 6.89 (t, J 9 Hz, 2H, C-3 and C-5 protons of 4-(4-fluorophenyl)), 7.11 (t, J 9 Hz, 2H, C-3 and C-5 protons of 5-(4-fluorophenyl)), 7.39 and 7.27 (2 dd, J 9 and 6 Hz, 4H, C-2 and C-6 protons of both 4-fluorophenyls).

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